Heat exchangers commonly include arrays of tubular conduits in parallel with one another and collectively between a fluid inside, at one temperature and pressure, and another fluid outside at an unlike temperature (and pressure). The tubular walls are designedly thin enough for ready heat conduction through them but thick enough to last through many cycles without leaking, as a leak incapacitates a heat exchanger sooner or later, usually rather promptly. Other tubular conduits, especially in chemical processing plants, contain noxious fluids capable of considerable damage and injury if released into their surroundings.
In the event of leakage of a tubular conduit whose physical integrity may have such undesirable consequences, efforts are often made to plug the leaking tube, whether to enable operations to continue operations, facilitate maintenance, protect the environment, save the contents (and money), etc. Plugging is complicated under any circumstances and is especially difficult where, as is common, the tubular interior is subjected at any time to a higher pressure than the exterior. A plug satisfactory at low pressure may leak or even be blown out at a higher pressure inside than outside.
Existing methods of attacking this problem focus upon inserting the smaller end of a tapered stopper manually into the bore of such tubular conduit and applying force to its larger end, usually intermittently as by hammering it, until a substantial part or all of the stopper has entered the bore. Unfortunately, such procedure can not lodge a stopper sufficiently tightly to preclude its subsequent dislocation and consequent leakage or outright expulsion at high fluid pressures applied to the plugging stopper from upstream. My invention deals with the foregoing problems and solves them.